Searches of extensive data sources often provide many results, which can span multiple screens or pages on the requesting user's display interface. In an attempt to highlight the most relevant results, search tools can use automated algorithms to rank-order the results in a list. Nonetheless, it is not unusual for search results to fail to include the desired target information at the top of this list. If a search returns an extensive list of results, a document desired by a user may actually end up being listed on page 3 or 4 or further down in a multi-page list of search results. The user may altogether miss the desired search result if the list of results is too lengthy to conveniently browse. With existing search tools, users are generally left to their own creativity when the time comes to refine a data search to hone in on the desired results. In addition, the standard approach of deciding on and typing in additional keywords raises a perceptible barrier to users who may be pressed for time. When faced with disappointing search results, users may often give up after one or two attempts to compose and enter revised search terms.
Such failures arise for a variety of reasons. For example, the user may not have carefully selected the search terms. As another example, the user may not be aware of the right search terms that would obtain the desired results. The latter example illustrates a particular problem faced by users: if the users knew exactly what they were looking for, they could rely less on the sophistication of the search engine. It would be helpful to have search tools that can guide a user to better formulate a search request. Similarly, it would be helpful to have search tools that can assist a user to better refine the results that are obtained in their initial searches.